This invention relates generally to absorbent materials, and more specifically to, various litter compositions used for the control and removal of animal waste.
Known lifter compositions are fabricated primarily from one of five materials: clay; vegetable matter such as grass, hay or alfalfa; wood chips, shavings or sawdust; and paper, such as shredded, flaked or pelletized paper, and Silica Gel. Known clay litters are prone to produce dust, and the tracking of this dust out of the litter pan by the animal. Further, production of such clay litters results in a large quantity of dust being produced, sometimes referred to as clay fines. Clay fines present a problem to litter manufacturers because the fines are a waste product and require disposal. In addition such clay products are not biodegradable.
Sodium bentonite clay is one known material used in the production of animal litters and is known for its excellent absorption and clumping qualities, as well as for odor retention. Some litter products are composed of 100% sodium bentonite. However, sodium bentonite is relatively expensive compared to other litter components. Therefore, attempts have been made to reduce the amount of sodium bentonite in clumping litters, for example, mixing pellets of non-absorbing clays with pellets of sodium bentonite clay in varying ratios. However, in these known litters, the properties which are most desirable in the sodium bentonite have been underutilized as most of the clumping and binding qualities of sodium bentonite occur at or near the surface of the clay. In ‘regular’ 100% bentonite litter, the granules are composed of 100% sodium bentonite. In these granules, the center typically does not swell. Therefore, in one embodiment of this invention, a swelling agent is coated on the surface of a non-swelling seed particle. Since moisture does not typically propagate to the center of individual granules, only the surface of the granule is coated with a swelling agent, resulting in a cost effective and efficient use of the swelling agent.